This invention relates to a process for the preparation of dinitronaphthalenes.
Dinitronaphthalene can be prepared by nitrating naphthalene or nitronaphthalene with a mixture of nitric acid and concentrated sulphuric acid (German Pat. No. 117,368, B.I.O.S. -- Bericht (B.I.O.S. Report) 986, part II, page 429 and Hodgson, Whitehurst, Soc. 1945, pages 202 to 204). The dinitronaphthalene formed by the nitration forms a viscous slurry with the concentrated sulphuric acid and the dinitronaphthalene cannot be separated from this. In order to isolate the dinitronaphthalene it is necessary to dilute the reaction mixture with water.